플러터챌린지 2일차 심화문제 - 신현호

readme.md

플러터챌린지 2일차 심화문제 - 신현호

Created with <3 with dartpad.dev.

main.dart

import 'dart:math';

import 'package:flutter/material.dart';


void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'HelloAnimation',
      debugShowCheckedModeBanner: false,
      home: HelloAnimationScreen(),
    );
  }
}

class HelloAnimationScreen extends StatefulWidget {
  @override
  State<HelloAnimationScreen> createState() => _HelloAnimationScreenState();
}

class _HelloAnimationScreenState extends State<HelloAnimationScreen>
    with SingleTickerProviderStateMixin {
  late AnimationController _controller;
  static const double starSize = 45.0;
  static const double starRotations = 10;
  double _top = 0;
  double _left = 0;
  bool isPlus = false;

  @override
  void initState() {
    super.initState();
    _controller = AnimationController(
      duration: const Duration(seconds: 5),
      vsync: this,
    )..addListener(() {
        if (_left < MediaQuery.of(context).size.width * 0.01) { isPlus = false; }
        if (!isPlus && _left > MediaQuery.of(context).size.width * 0.99) {
          _top += starSize;
          isPlus = true;
          if (_top >= MediaQuery.of(context).size.height - starSize) {
            _top = 0;
          }
        }
      })
      ..repeat();
  }
  
  @override
  void dispose() {
    _controller.dispose();
    super.dispose();
  }
  
  void _changeLine(TapDownDetails details) {
    setState(() {
      _top = details.localPosition.dy;
    });
  }

  @override
  Widget build(BuildContext context) {
    return GestureDetector(
      onTapDown: _changeLine,
      child: Scaffold(
        backgroundColor: Colors.black,
        body: Stack(
          children: [
            AnimatedBuilder(
              animation: _controller,
              builder: (context, child) {
                final size = MediaQuery.of(context).size;
                final horizontalMovementLength = size.width;
                final animationValue = _controller.value * horizontalMovementLength;
        
                _left = animationValue % horizontalMovementLength;
                double rotation = _controller.value * starRotations * pi;
        
                return Positioned(
                  left: _left,
                  top: _top,
                  child: Transform.rotate(
                    angle: rotation,
                    child: const Icon(Icons.star, size: starSize, color: Colors.yellow),
                  ),
                );
              },
            ),
          ],
        ),
      ),
    );
  }
}